1. Field of the Invention
This invention relates to polymer-polymer blends.
2. Description of the Prior Art
A new class of polymers, hereafter referred to as "polyglutarimides", having a very interesting range of useful properties have been provided by Kopchik U.S. Pat. No. 4,246,374. Kopchik himself disclosed various possible modifications of the polyglutarimides, as did Mueller in U.S. Pat. No. 4,254,232 and Weese et al in U.S. Pat. No. 4,217,424.
Styrene-acrylonitrile ("SAN") copolymers, of course, are well known, as are various multiple stage polymers having styrene-acrylonitrile copolymer as one stage.
Various attempts have been made to improve the impact strength and other properties of the polyglutarimide family of polymers, as have various attempts been made in the SAN field to improve various properties or property balances.
Because of unfavorable thermodynamics (entropy of mixing) polymer-polymer solutions are rare. Various the theoreticians have attempted to predict polymer-polymer miscibility via complex cohesive energy density calculations or the use of Group Molar Attraction Tables, but there is no good correlation between theory and actual practice via experiments.